Page 1 of 1 Lotus Engineering, the engineering consultancy division of Group Lotus Plc has developed a bio-ethanol E85 version of the Lotus Exige. The research vehicle is a true Lotus (it weighs just 930 kg unladen) and is called the Lotus Exige 265E. 265 indicates the approximate horsepower and is consistent with the naming strategy of other one-off and limited run Lotus variants such as the Lotus Sport Exige 240R; the E indicates the environmentally favourable bio-ethanol E85 fuel (85% ethanol alcohol and 15% petrol / gasoline) that powers this extremely high performing sportscar.

Key to this performance is a slightly modified version of the 2ZZ VVTL-i supercharged and intercooled high revving 4-cylinder engine from the standard Lotus Exige S. This now gives an estimated set of performance figures that would thrash the majority of "Super-Unleaded" performance cars: 0-60 mph in 3.88 seconds, 0-100 mph in 9.2 seconds and a top speed of 158 mph! In fact, the Lotus Exige 265E is probably the world's quickest road-legal E85 bio-ethanol car.

Key changes have been made to the fuel system, the engine calibration and the four fuel injectors mounted on the inlet manifold have been enlarged. Two additional fuel injectors have been fitted at the Supercharger inlet to increase the amount of fuel being injected in to the engine under higher engine loads and to further cool the charge air prior to combustion.

Bio-ethanol E85 is a fuel which is a mixture of 85% ethanol (an alcohol) and 15% petrol / gasoline. The bio-ethanol can be made from bio-mass plant crops such as cereals, sugar beet, sugar cane and wood. As these plant crops grow, they absorb carbon dioxide from the atmosphere, which then partly offsets the carbon dioxide (CO2) emissions produced during the burning of the bio-ethanol fuel in the car's engine.

Different bio-fuels were considered for this research project, bio-methanol, bio-ethanol and bio-butanol. E85 bio-ethanol was the finally chosen as the fuel as its characteristics allowed the engineering project team to enhance the engine performance. The fact that this vehicle uses a pressure charged engine provided even more opportunity to exploit the performance characteristics of a high-octane fuel. Ethanol has a high octane rating, which allows an optimum timing for engine ignition and has a fast flame speed in the cylinder, so the fuel burns faster, increasing the efficiency of the engine.

The beauty of ethanol is its ability to produce more power in the engine than with conventional petrol / gasoline fuel. The Lotus Exige 265E now produces 264 hp (197 kW, 268 PS) at 8000 rpm, and 184 lbft (249 Nm) of torque (at 5500 rpm), up by 46 hp (34 kW, 47 PS) or 21% and 25 lbft (34 Nm) or 16% over the standard petrol / gasoline Exige S. With the total weight of approximately 930 kg (unladen), the power to weight is approximately 283 hp / tonne (211 kW / tonne, 287 PS / tonne).

Ethanol has less stored energy per unit volume than gasoline so the fuel economy is less, however as E85 ethanol is 85% sourced from renewable bio matter, there is a net reduction in carbon dioxide (CO2) Page 1 of 1